Retractable Y-shaped foils, adjustable in three dimensions

Inspired by the appendages of the America's Cup foiling monohulls, these Y-shaped foils have a wingspan of over 5 metres. They are designed to generate powerful lift, increase power and offer a wide range of adjustments to optimise flight at every point of sail and in all conditions. Beyond their impressive size, these foils feature many unique innovations.

Revolutionary U-shaped rudders

These are probably the most visually striking innovations on the new Maxi Edmond de Rothschild. To fly high above rough seas while maintaining control, the team wanted very long rudders that would remain in contact with the water. The challenge is that longer rudders tend to flex under load, severely affecting steering and the efficiency of their lifting surfaces. A new geometry was needed to give these appendages maximum stiffness, resist cavitation and ultimately improve control of the boat and make better use of its power. The result is a set of U-shaped rudders over 4 metres long, a metre longer than those on Gitana 17. Their shape, reminiscent of a tripod or an inverted π, is only the visible part of what makes them so distinctive.

A daggerboard optimised to stabilise the boat and limit cavitation

With its wide span, the daggerboard resembles an aircraft tail assembly, with two adjustable flaps: one on the vertical section and the other on the horizontal section, the distinctive “manta-ray wing”. On Gitana 18, the innovation is to position this wing behind the vertical part of the appendage, rather than directly beneath it, to minimise flow disturbance and cavitation.

Rig: adjustable spreaders to control mainsail power while sailing

Gitana 18’s mast is 1.50 metres taller than its predecessor’s. The boom is also shorter, creating a more slender sail plan. The major innovation is a set of spreaders that can be adjusted while sailing to bend the mast fore and aft. Actuated by hydraulic rams, these spreaders can pivot through 35 degrees to adjust the bend in the middle of the mast. This unprecedented system allows the sailor to control mainsail power: adding depth in light winds to take off sooner, or flattening the sail to reduce power at high speed or in strong winds. Adjusting the depth, and therefore the power, of the mainsail can also save a solo sailor time and energy by reducing the need for risky manoeuvres or headsail changes.

Central hull:
an integrated, structural coachroof

The naval architects and Gitana design team wanted an exceptionally stiff, structurally robust platform. This applies both to the floats, which must withstand heavy loads from the foils and rudders, and to the central hull, which is subject to torsion. The enclosed coachroof is integrated into the hull and contributes to its structural strength. Inside, the cockpit brings all sail-handling controls together, with ergonomics shaped by many hours of design and development. The coachroof also stands out for the number and size of its windows. This configuration meets the visibility requirements of the Ultim class rules and gives sailors the best possible view to keep a visual watch.

20.09.2008

Gitana 13 heading towards Cape Finisterre.

par Gitana

The maxi-catamaran in the colours of the LCF Rothschild Group is continuing to make towards Cape Finisterre, which she is set to round tomorrow morning. However, current sailing conditions mean the boat is on a beam reach, which is proving far from relaxing, and requires all the energy from a crew which has already been put to the test by the past 37 days at sea. Though the end of this record attempt between Hong Kong and London is close – Gitana 13 will pass under the 1,000 miles to go barrier during the course of today -, the last few days at sea will be just as tricky. Indeed, harsh, upwind conditions lie in store for Lionel Lemonchois and his nine man crew.

There was evidence of a long night for the crew of Gitana 13 in the voice of Dominic Vittet this lunch time. By flirting with the centre of the low which is accompanying their course towards Cape Finisterre, the men of Gitana 13 have had to deal with winds bordering on 40 knots and short, big seas: “Last night we were shaken about every which way. We passed very close to the centre of the low – around 20 miles away – in order to gybe with a more favourable angle for making headway towards Finisterre. This option gave us winds of around 40 knots, but most significantly the seas were virtually on the nose, short, choppy and with three to four metre waves”.

In conditions we can best describe as harsh – especially with Gitana 13 making headway on a reach -, life aboard the maxi-catamaran is complicated: “On deck, the men on watch are totally wiped out; it’s a permanent hosing down! They are padded out in their foulies and all you can see is their eyes, reddened by the spray. Down below it’s not really any better, as sleeping is a real challenge, as is eating” said the onboard navigator. However, Lionel Lemonchois and his men are taking it all in their stride as they know that this is the price they have to pay to reduce the distance still separating them from the finish in London. At the 1315 UT position report, the maxi-catamaran equipped by Baron Benjamin de Rothschild still had 1,050 miles to go to reach the end of its voyage.

Sailing along the latitude of Lisbon this afternoon, the crew of the 33 metre maxi-catamaran was benefiting from a slightly more settled air flow – 25 knots, easing on the approach to the Iberian coast – to rack up the miles. Indeed a rendez-vous awaits them as they round Cape Finisterre, at the NW tip of Spain: “The steady NE’ly air flow we’ve been witnessing for several days over the Bay of Biscay doesn’t seem to want to leave. We’re now virtually certain that we’ll have to traverse this zone close-hauled in harsh conditions: a NE’ly of between 20 and 30 knots according to the grib files. That’s not great news for anyone here evidently and we’d been waiting for the outcome as you would the grand finale of a fireworks display! However, the quicker we arrive at the Cape the better the next stage will be” concluded Dominic Vittet.

Still positioned over 300 miles from Finisterre this Saturday afternoon, Gitana 13 is set to round the Spanish promontory late tonight or tomorrow morning and thus make her entrance into the Bay of Biscay.

A few figures
Gitana 13 left Hong Kong on Thursday 14th August at 07h55’32” (UT)
Saturday 20th September at 1315 UT, Gitana 13 was sailing at 39°00.97 N /14°15.60 W

Watch No1: Lionel Lemonchois (Skipper / watch leader / helmsman) / Olivier Wroczynski (trimmer /head of computers and power) / David Boileau (Bowman / head of deck fittings)

Watch No.2: Ludovic Aglaor (watch leader / helmsman) / Laurent Mermod (trimmer) / Ronan Le Goff (Bowman)

Watch No.3: Pascal Blouin (Watch leader / helmsman) / Ronan Guérin (trimmer) / Léopold Lucet (No.1, head of supplies and doctor)

Outside the watch system: Dominic Vittet (navigator)

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